Add changelog for 2.4.0
Add section about basecfg update.
Add new Java source files to copyright exclusion list.
Merge branch 'develop' into release-2.4.0
Minor edits to the 2.4 change log.
Cut release 2.4.0
Fixup release version for 2.4.0 release.
Merge pull request #1285 from wiredtiger/release-2.4.0

Add changelog for 2.4.0